Platen knob with telescoping clutch knob



Dec. 25, 1951 w, DQBSON 2,580,285

PLATEN KNOB WITH TELESCOPING CLUTCH KNOB Filed May 28, 1949 INVENTOR.

ing and other office machines.

Patented Dec. 25, 1951 UNITED STATES PATENT OFFICE PLATEN KNOB WITH TELESCOBING CLUTCH KNOB J William A. Dobson, West Hartford, Conn., as-

signor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application May 28, 1949,'Serial N 0. 96,127

The invention relates to platen rotating knobs and platen clutch controlling means for typewrit- Typewriters of conventional design embody-a platen roll and have a line-space mechanism to impart to a toothed line-space wheel on the platen incremental turning advances, thereby to linefeed the platen. A spring pressed element is usually associated with the toothed Wheel to detent it in any line-space position to which it is turned. To permit turning adjustments of the platen independently of the line-space wheel, as for example when ruled lines on the paper must be matched with the printing point, a clutch is provided which is adapted to'be opened and closed respectively to permit rotation of the platen either independently or connected with the toothed linespace wheel. The platen is usually conveniently turnable by a knob of appreciable size, and a relatively small control button projects usually endwise from said knob and is operable axially of the platen for control of said clutch.

In certain classes of work the knob and the button are used frequently and the operators hand must constantly switch from one to the other, which movements have been found awkward and inefficient to perform. In view of the above and other deficiencies of prior known platen rotating and platen clutch controls, it is an object of the invention to provide conveniently manipulative, efilcient control means for turning the platen and for operating the line-space clutch.

Particularly, it is also an object to provide such improved control means to the end of making platen rotation and clutch controlling action easier when one is to succeed immediately the other.

Another object is to provide in novel and efflcient telescopic association with a platen turning knob another knob which constitutes an extension of the turning knob and is movable axially of the platen to open and close a line-space clutch, said other knob being also conveniently turnable to rotate the platen.

A still-further object is to give the two knobs of said telescopic association such form that all the desired manipulations thereof can be performed smoothly by convenient motions of the hand.

Other objects and features will be in part obvious and in part pointed out particularly as the following description of a preferred embodimen of the invention proceeds.

. Referring now to the drawings: Figure Us a sectional front elevation of, a line- 6 Claims. (01. 197 '123 space clutch mechanism, including also a platen rotating knob in novel association with a dualpurpose platen turning and line-space clutch controlling knob, the clutch being shown in closed condition.

Figure 2 is'a view similar to Figure 1, but show ing the line-space clutch open.

Figure 3 is an end view of the platen turning knob, the dual-purpose'knob having been omitted.

Figure 4 shows the knobs of Figures 1 and 2 in full elevation.

Referring to Figures 1 and 2, a platen roll H1 is carried upon a platen shaft H by means of a hub l2 which has a set screw |3 therein rendering the platen unitarily assembled upon the said shaft. 'Also carried fast on said shaft, as by'a pin id, is a clutch unit comprising a flange I6. This clutch unit is of conventional Underwood manufacture and comprises also a disk ll, which by studs, not shown, is rigidly united with the flange H3. Upon said flange l6 and disk I? is accommodated an annular member or ring [8 having line-space teeth 20, such ring being commonly known as'the line-space wheel. Caged Within the flange It, the disk I! and the linespace wheel I'B are a pair of clutch shoes 2| and a pair of clutch shoe operating arms 22. Said clutch shoes and arms are of conventional structure and substantially a shown in the patent to Hel-mond, No. 1,432,695, dated October 17, 1922. By means not shown, but disclosed in said patent, the brake shoes are constrained to turn always with the flange It. In the closed position of the clutch seen in Figure 1, the clutch shoes 2| are shown pressed outwardly into firm frictional contact with the line-space wheel by an annular cam member 23 which spreads. the clutch operating arms 22 and, by means not shown, spreads the brake shoes 2| at great leverage outwardly. 1 The cam member 23 is slidably supported on the platen shaft. For turnably associating the platen upon a supporting frame 25, there is carried loosely on the platen hub l2 a bushing 26 which is annularly grooved as at 2 1 for seated accommodation upon a saddle plate 28. The latter is rigidly carried on the frame 25,

and appropriate means, not shown, hold the bush- 3| there is provided a dual-purpose knob 33. This dual-purpose knob 33 is carried upon pins 34 extending through perforations in the core 32 of the knob 3|. The said knob 33 is preferably molded fast onto roughened ends of the pins 34, as shown. Said two pins 34 are in control over the clutch-ccontrollingtcam element'23' by means of lost ---motion "connections provided by i -heads 35 on said pins situated in an internal annular cavity 36 of the cam element 23.

The clutch is shown in closed @conditionin Figure 1, and this condition is theresultdi'ghaving pressed the dual-purpose knob 33 axially in the direction of the platen turningrknobifl The latter knob has a large internal axiala-reoess338'3 forming a large diameter sleeve 40, and the dualpurpose knob 33 comprises adjacentesaidisleeve 40 a gripping portion 4| merging into a portion 42 which extends into said sleeve in atelescopic association therewith. The knob 3! is apprezxciably .:larger:than; the knob.733uandatapersadown -tozthe :extr emityofisleevef 4 3 :whichis thinrxvvalled.

- On:: the .otherrhand the,;gripping:portion 4 |.if the .;dual,-purpose 1knobisis larger; than thei portion 42 and tapers down thereto. In Figure Zthe-Qlutoh iseim an: open;condition,;and:it will-.1be seen sthat the dual-purpose knob ,33;hasgbeen pulled outxz-wardly from'themain platenturning knob 3 l ;,but

. Jthe; knob; P01131011AZIJiSgzSfiill partially contained siwith-inz'thes sleeve 40. For this :reason there is never a void between the two knobs-wherein the LIODEITfitOlES; fingers are liable; to "become p nched 501' caught when the sdualripurpose ;knob 33 :is

moved to 161056 :theyclutch.

:Thernovel telescopic, inter-arrangement of the; i'tWO knobsrhas gmanyiadvantages. -,It.; makes;possibletazquick"switch;.;of thezzoperators handfrom :eitherrone ztO'ithG'OthGl knob in;,a smooth; and

iiastwprocedure. :The :operatortzmaya roll? a .work .-;;sheet. into: thexmachine by turning the main;knob-.

a3 l saridL-inrorder tog-iefiect Jthema fine adjustment -:-of ithe platen :;independently :of i; the 's. lineezspaee wheel l 8,;lthe.;operators fingerssrmaythen the? slid srconveniently. ontottherknobs33 to displaoeritiout- -wardly intanorhbil'le'd movement for; olutchzopen ting action. :1 Insliding thei fingersgoutwardly; they close in automaticallyzon theitaper otizhei gripping portion 4 lLOfil theknob ,33. ;Moreover,:;the; clutch aopeningj movement of thei.dual+purposez.:knob:33

may be continued aturning motionxwithout, "transfer of the hand back:onto zthexknobni. w It will be further-noted:thatuinsliding the knob 33: outwardly, portions of the operatorsafingers mayeremain on, .or may convenientlyilbeamoved back onto;the' larger-knob" 3 ltfona combined hold -:on b'otl1" knobs" to turn 'the platen. C'I'he? itaperttof i-thekn'ob'33 and-the taper of the sleeve '40 present an annular depression which is ypleasingi foriea firm finger hold as w'ellas in appearance.

Foreitecting closure or: the clutch;-'the-opera-' "tor may place the entire hand on the combined ='-kn'ob structure and may exert pressure against "the end-of the knob 33 by the palm of the hand. Despite the fact that the diameter of the dualpurpose 'knob- 33 is nearlythat of the main' knob .vr.

3 no pinching :of anypart of the operator s "hand is" possible=when theknob 33 is, pushed :in. This is in view of the-telescopic association ofbthe twoknobs.

In the closedpositionof the clutch,the annularf 0am member=23 is prevented from 'slippingoutwardly'from the clutch, substantially in themanner as disclosed in the patent to Helmon'd,"iNo. 1,150,366, "dated August 17, 1915. specifically ca spring :pressed i look "pawl i 44,- pivota'lly accom- 4 modated in a slot of the knob core 32, isassociated with a lock pin 45 to move partly across an end thereof whenever the clutch assumes fully closed position, see Figures 1 and 3. In the open position of the clutch the pawl 44 bears against one of the pins 34 and is entirely free and clear iof'"'the-,-pin 45, which pin similarlytoEthe pins 34 vsis Y. slidablya accommodated link the knob core 32. The pin 45 moves axially in unison with the 31m :yclutch controlling cam 23, and to this end forms aninterlockingengagement with the cam menipb'er fby means of an internal rim 46 formed on thelatter by the cavity 36 and in view of an "annularegroovesinithe pin. In the closed posivtioniof the clutcha seen in Figure 1, the pawl 44,

-unden'spring tension, comes to lie in a cam-form- ,ing reduction 4'Lof one of the pins 34 and swings behind the endof the pin 45.

Ii-Only up0n deliberate movement of the latch 33 outwardly from the, Figure 1 position, and at snciotherstime,ithexeamliisallowed;to'm vep t- -=-.wardlyxtqopen;clu ch position assee pinFi urea. Initial outward movement; of thegknob -33 causes firsteansoutward displacement of the pawl? by 3C-fi01l0fj$hQ pin; reduction 41,0n such :pawl. 'JI'he heads-a;of the,;,two;;pins 7 34 durin uch movement willflhave no effecton the cam; element, 23in jthatcth ey moveiree ly inrthe cavity 36 until they 1. engagev the rim-:46. Further outward, movement 30 10i; ztherdual puppose knob..-3 3ais then: transmitted ito the.;:,ca-m 23;;and results in the. openingofrthe :clutch.

"The gknob: embodies unitarily .thereonaa tubular 7 member 48 which covers the-pins 34, and part of; the cam lmember fi.

;-I Iaving sspecifically;described.v the invention in eta; preferred eform, what; is ;;O.la imed is:

;-flh .;o ln ination (with atur a l rplat n 11 .vlin filace wheel and, a; clutch to; c nnect; or=;d is- 40 Y c n -th platentfromt e zlin n p e ai -h eh-p e urning1.kne :forl:t e; pl ten; coaxial there ith, a dual-purpose knobiiofilarge diarneterjalso coaxial with the ;p laten.zfor, turning the; platenand sfe pa rollin a ti o zsa-i clutehemean aa v'socia in ai ;du ..-lpmrpose n -wi hhel pl ten taticmthereof .asiwellsas. for opposite cl t h- .'-for re,

controlling movements axially -;;Of ;the pl aten, c amean stovopeneand close: said; clutch ;,-sa p- ,ite movements oizsa-iddual-anurpo ezknob,1on 5O "QfLSfiiidikDQbSi i in pron-flie Withaawylindrifial i V ecess (it-large. diameter. QQa iahWith the platen storming: on. suehaz inohzar sieevepf lar ed ame er. and the other knob comprisin "812130115011: in; teleconic;iinternalgzassociation WU 31 saidzjsle veean emnr net-further an 23813-115? neighb rinsysrm- -nin aportion; remainingna vtay o tside ofusa-i Jsleevexand sharing iameter substantial-lyea leastiasierge as thesaid firstpor ion otthezknob, -wherebyctheptwdknobstaresteleseonieal yassocii. ated-i and th splaten s ,xturnab ealwaysbv i h uoiv hectwdknobs.

szm'lihe invention set forth in claim 1, esaid s'sleeve -bei --;thin-Wa11ed; at; i s; Op i d. an increasing diameter; the direction;.away from rthezgnippin icportiom f.;sa:id.= otherzknob.

3.- ;.The;rinvention.:aset .iorth sin cla m vlsrsaid grippingtportionzandizsaidssleeize';beinguof;diminslshing diametereaxial-ly. toward each other.

4. The combination with a turnable platenma Z0 -=1ine=space wheel; andzaclutchuto:connectaoridiseeonnect'xthe platen"; from; the. lineespace; wheel; :of tiatturningeknob fontheplaten coaxialzand'ffixedly associated therewith, .asadualepurpose :knob fiOf large diameter also coaxialiwith the .platen,'%1for 1 turning; the platen and .foracontrolling action on said clutch, means associating said dual-purpose knob with said turning knob for turning it, and for opposite clutch-controlling movements axially of the platen, means to open and close said clutch by said opposite movements of said dualpurpose knob, said turning knob having coaxially therewith a cylindrical recess forming a large diameter sleeve, and the dual-purpose knob comprising axially adjacent to said sleeve a gripping portion remaining always outside of said sleeve, and comprising further a portion extending telescopically into said sleeve, said gripping portion having a diameter substantially at least as large as the portion which extends into said sleeve, whereby the dual-purpose knob is telescopically associated with the turning knob and whereby both knobs are manipulative for their respective purposes at all times.

5. The combination with a platen shaft, a

platen turning knob carried fast on an end of said shaft, a line-space wheel concentric with said shaft and axially spaced from said knob, and a clutch carried on said shaft and operable to clutch the platen shaft for rotation with or independently of said line-space wheel; of a dualpurpose knob concentrically arranged with said turning knob, means to mount said dual-purpose knob for sliding movement in concentric relation axially on said turning knob and turnably therewith, said mounting means comprising a plurality of rods extending rigidly from the dualpurpose knob through the turning knob in parallel to the platen shaft for clutch operating action, said turning knob having an axial recess forming a large-diameter sleeve, and the dualpurpose knob comprising axially adjacent to said sleeve a gripping portion substantially of a diameter at least as large as the interior recess of said sleeve and comprising further a portion extending into said sleeve in a telescopic association 6. The combination with a turnable platen, a line-space wheel, and a clutch to connect or disconnect the platen from the line-space wheel; of a turning knob for the platen coaxial and fixedly associated therewith, a dual-purpose knob of large diameter also coaxial with the platen, for turning the platen and for controlling action on said clutch, means associating said dual-purpose knob with said turning knob for turning it, and for opposite clutch-controlling movements axially of the platen, means to open and close said clutch by said opposite movements of said dualpurpose knob, said turning knob having coaxially therewith a cylindrical recess forming a large diameter sleeve, and the dual-purpose knob comprising axially adjacent to said sleeve a gripping portion remaining always outside of said sleeve, and comprising further a portion extending telescopically into said sleeve, the said gripping portion closest to the other portion being substantially of the same diameter as the cylindrical recess in said sleeve, and being of increasing diameter in a direction axially away from said sleeve.

WILLIAM A. DOBSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,057,365 Ursbruck Mar. 25, 1913 1,432,695 Helmond Oct. 17, 1922 FOREIGN PATENTS Number Country Date 96,159 Austria of 1924 

